Process of treating marine oils



Patented June 6, 1939 I e u e UNITED STATES PATENT. OFFICE PROCESS OF TREATING MARINE OILS William Hassard, Vancouver, British Columbia, Canada, assignor to David B. Boyd, Los An gelcs, Calif.

No Drawing. Application October 23, 1937, Serial No. 170,643

9 Claims. (01. 260 -406 This invention relates to a process of treating A further object is to provide amethod of treatmarine oils such as, for example, sardine oil, piling marine and animal oils whereby the treated chard oil, whale oil, etc., whereby said marine oils oil is characterized by a higher iodine number are rendered more suitable for use in paints or and a lower stearin content.

5: those uses which require improved drying char- A further object is to provide a method of acteristics as, for example, in the manufacture of purifying and stabilizing marine and' animal oils linoleum and the like. The method is also appliby the use of permanganate solutions. cable to the treatment of vegetable oils such as Numerous other objects, uses and advantages lin ed, live, et of this process will become apparent to those Heretofore fish oil such as, for example, sarskilled in the art from the following detailed de- 10 dine oil, has been deemed unsatisfactory for use scription. In order to facilitate understanding, in paints because such oils are semi-drying only reference will belspecifically made hereinafter to a d do n t f r a, n n-ta k h d film when fish oils such as, for example, 'pilchard oil, but it subjected to oxidation or weathering. This is priis fi d. that these specific Oils a e marily due to the fact that these marine oils conmentioned asexamples and illustrations and. the t m appreciable quantities of th higher fatty invention is not limited thereto but instead is acids such as, for example, palmitic and stearic Capable of being p oyed n Va ious stearinacids, the solid mixture of these acids being known Containing Oi sin the trade as stearin. Some attempt has been As stated hereinbefore, the method includes the inade in the past to improve these oils by winterstep of producing n nt ate Contact between 20 'izing them, that is, by chilling them to a very low the oil to be treated and an aqueous solution of temperature so as to solidify and precipitate Potassium p ga te- Ordinarily, the. D stearin and then remove the same from the oil by manganate Solution is used in the propo t on Of filtration or otherwise. This process is expensive between ut to 1.3 volumes of solution to 1 and t atisfactory volume of oil, although prolonged agitation or 25 Another requirement of a drying or paint 1 1 contact of 1 volume of oil with 0.1 volume of th t t have relatively high iodine number, the solution will also produce the desired results. higher iodine number indicating a higher content 7 The aqueous $0111ti0n$ p e ably Contain from of unsaturated substances which are capable of o t to 2.0% O DOtaSSiUm permanganate,

absorbing oxy e nd forming a suitably ha d, best results being obtained on relatively fresh 30 dry film when used as a paint, Practically all Sardine pilchald 011 With fl out 1 fish oils have an iodine number which is materialto 0f DOtaSSium permanganate. W en an Old, ly below the minimum iodine number acceptable Partly rancid dark Oil is being t eated, then bythe paint trade as a drying. oil. the aqueous solutions may contain from 0.8% to The present invention is directed toward a as high as of potassium permanganate; 35

process which may be readily carried out on vari- When these higher concentrations of permanous marine and animals oils for the purpose of ganate are employed, a S aller Volume of such improving their drying characteristics and rensolution can be used volumeof dering the on much more suitable f those uses Contact between the oil and aqueous solution 1s 4 which require Oils of the drying type Generally preferably accomplished at atmospheric tempera- 40 tures or temperatures below about 150 F; The oil to be treated is therefore not subjected to sufliciently high temperatures, for'example, temperatures of 250 F. or more, which cause polymerization or heat-bodying of the constituents. Con- 45 carrled out at relatively low temperatures and 1s tact between the aqueous solution and the on may not to be confused with a heat-bodying process. It appears probable that the stearin and higher 3: i ig g ?g ifr f gg f g g: fatty acids such as palmitic and stearic, are con mang'anate Solution are e they Shouk? be verted during the process into unsaturated comthoroughly agitated so as to produce intimate poullds compounds wtuch are capable of contact. Ordinarily a quick-breaking emulsionis Sorblng y n V y Teadllyformed by such mixture. The time of contact It is an. object of this invention, therefore, to does not'appear t be t l and t mdisclose. a provide a method Of increasing the ing which the oil and aqueous solution are in constated, the invention comprises treating the oil with an aqueous solution of potassium permanganate and then separating the aqueous solution from the treated oil. The process is preferably drying power of marine and animal oils. tactwill vary with the size ofthe batch, the"type 55 of equipment used, and whether the process is operated as a batch or as a continuous process.

After such intimate mixture has been attained the mixture or emulsion is separated by gravity as, for example, by settling or centrifuging. The use of centrifugal separators is desirable since these devices are capable of separating the emulsion and separately discharging treated oil, an aqueous phase and solid material.

It will be found that the oil treated as above described will have a higher iodine number than i the original oil. Furthermore, its ability to absorb oxygen will be greater and the drying time of the oil will be shorter. No appreciable change in specific gravity, viscosity, acid number and saponification number would have taken place although the percentage of unsaponifiable'matter may be slightly increased.

In one specific example of the process a pilchard oil was treated with an equal volume of an aqueous solution containing 0.07% of potassium permanganate at atmospheric temperatures and after thorough agitation the mixture was passed through an S. K. F. centrifugal separator. Portions of the treated and untreated oils were then tested and the following results were obtained:

Raw Treated Mark No 1 No. 2

Specific Gravity at F 0. 030 0. 930 Iodine number (Wijs)... 168 180 Stearin 0. 33% 0. 08% Viscosity. Saybolt Universal at F l3? secs. secs. A cid number 0. 09 0. (l0 Saponification number 192 191 Unsanonifiable ni. 0. 20 0. 41% Drying time 50 hours 42 hen-rs Oxygen absorption Percent Percent e "e in Weigl1taftei' 1. 5 3. 0 48 hours 5.0 7. 4 96 hours 11.0 10. 5

For purposes of comparison, a raw linseed oil having an iodine number of 1'77 was also treated to determine the amount of oxygen which it would absorb and it was found that such raw linseed oil increased only 1% at the end of 8 hours, 2% after 48 hours and 7.2% after 96 hours. These results very definitely show that this pilchard oil is more efiective as a paint oil than even raw linseed oil. The oil treated in this example was fresh pilchard oil of high quality and much greater relative improvement is obtained by this process on lower grade oils.

In the above tabulation attention is specifically called to the fact that the viscosity of the treated oil was slightly lower than that of the raw oil and that the stearin content had been reduced from 0.33% to only 0.08%. The iodine number, however, had been increased from 168 to 180.

It is to be remembered that no mineral acids are added to the aqueous solution with which the oil is brought in contact. The color of the oil remains practically unchanged although minor changes in coloration are sometimes evidenced.

In certain instances the raw untreated oil may be subjected to afiltration or preliminary clarification for the purpose of removing solid particles of flesh and the like. Furthermore, it is sometimes desirable to add a small quantity of a material such as finely divided talc, diatomaceous earth, short asbestos, tailings or fines, etc., to

the mixture or aqueous solution and oil during agitation. When such mineral constituents are used they may be added in amount ranging from about 0.1% to 1% by weight of the oil. During subsequent separation of the emulsion into oil and aqueous constituents, the finely divided insoluble mineral or other solid matter exerts a clarifying effect, thereby tending to produce a brilliant or polished oil. Activated carbons or the like may also be added for the purpose of partially bleaching the oil.

I claim:

1. A method of treating marine and animal oils to increase their iodine numbers and drying characteristics which comprises: producing intimate contact between the oil to be treated and an aqueous solution of potassium permanganate in the absence of mineral acid, and then separating the mixture to separately discharge treated oil and an aqueous solution.

2. A method of increasing the drying power of marine and animal oils which comprises: mixing a dilute aqueous solution of potassium permanganate with a marine or animal oil to be treated, in the proportion of between about 0.3 to 1.3 volumes of solution to 1 volume of oil, and then gravitationally separating the oil from the mixture.

3. A method of increasing the drying power of marine and animal oils which comprises: mixing a dilute aqueous solution of potassium permanganate with a marine or animal oil to be treated, in the proportion of between about 0.3 to 1.3 volumes of solution to 1 volume of oil, at a temperature below about F., and in the absence of added mineral acid, and then gravitationally separating the oil from the mixture.

4. A method of increasing the iodine number and decreasing the stearin content of marine and animal oils which comprises: mixing a dilute aqueous solution of potassium permanganate with a marine or animal oil to be treated, in the proportion of between about 0.3 to 1.3 volumes of solution to 1 volume of oil, at a temperature below about 150 F., agitating the mixture in the virtual absence of added mineral acid, and then gravitationally separating the oil from the mixture.

A method of decreasing the stearin content of marine oils and increasing the drying power thereof, which comprises: producing intimate contact between a marine oil to be treated and a dilute aqueous solution of potassium permanganate, at temperatures insufficient to heat-body the oil and in the virtual absence of added mineral acid, and then gravitationally separating the oil from the mixture.

6. A method of decreasing the stearin content of marine oils'and increasing the drying power thereof, which comprises: producing intimate contact between a marine oil to be treated and a dilute aqueous solution of potassium permanganate at temperatures insufficient to heat-body the oil and in the virtual absence of added mineral acid, adding. a small proportion of finely divided solid material to said mixture, and then gravitationally separating the oil from the mixture.

'7. A method of increasing the drying power of. marine, animal and vegetable oils which comprises: producing intimate contact between the oil to be treated and an aqueous solution containing from about 0.05% to 2.0% of potassium permanganate "at temperatures insuflicient to heat-body the oil, and then gravitationally separating the oil from the mixture.

8. A method of increasing the drying power of marine, animal and vegetable oils which comprises: producing intimate contact between the oil to be treated and an aqueous solution containing from about 0.05% to 2.0% of potassium permanganate at temperatures insuificient to heat-body the oil, in the proportion of between about 0.1 to 1.3 volumes of solution to 1 volume of oil, and in the virtual absence of added mineral acid, and then gravitationally separating the oil from the mixture. 

